红娘鱼降血压肽的酶解制备工艺优化及酶解产物的抗氧化活性研究

为有效利用红娘鱼制备降血压肽,以红娘鱼鱼糜为原料提取蛋白,并对其进行酶解制备降血压肽。以血管紧张素转换酶ACE抑制率和水解度为指标,通过响应面分析法对酶解红娘鱼鱼糜蛋白制备降血压肽的工艺条件进行优化,并对最优条件下制备的酶解产物进行分子量和抗氧化活性测定。结果表明,碱性蛋白酶是制备降血压肽的最适蛋白酶,响应面法优化制备降血压肽的最佳酶解条件为pH值9、酶与底物的比值(酶底比)1.4%、温度54℃、时间2 h,此条件下酶解制得的降血压多肽ACE抑制率理论值为88%,实际值为89.3%;经高效液相色谱(HPLC)分析可得酶解产物相对分子量<2 000 Da。通过测定酶解产物样品的1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除率、羟自由基(·OH)清除率及还原力判定其体外抗氧化活性,结果表明酶解产物具有较强抗氧化活性。本研究结果为红娘鱼的高值化利用提供了数据支持和理论基础。

Optimization of Enzymatic Preparation Process of Peptides From Lepidotrigla kishinouyi by Response Surface Methodology and the Antioxidant Activity of the Enzymatic Hydrolysis Products

In order to utilize thelepidotrigla kishinouyi to obtain ACE inhibitory peptide effectively, the Lepidotrigla kishinouyi was used as the material to extract the myofibrillar protein, and then the antihypertensive peptide was prepared by enzymatic hydrolysis. Angiotensin converting enzyme (ACE) inhibitory activity and degree of hydrolysis (DH) of the enzymatic hydrolysates were selected as indexes, and the parameters of enzymatic hydrolysis of lepidotrigla kishinouyi surimi protein were optimized by a response surface analysis (RSM, Response Surface Method). The molecular weight and antioxidant activity of the enzymatic hydrolysates prepared were determined under the optimal conditions. Alkaline protease was the best enzyme for preparing antihypertensive peptide, and the optimal enzymatic hydrolysis conditions for the preparation of antihypertensive peptide by response surface method were obtained as follows: enzyme-substrate ratio of 0.4%, hydrolysis temperature of 54℃, pH 8.6 and enzymatic hydrolysis time of 2 h. Under this condition, the theoretical value of ACE inhibitory rate was 88%, while the actual value was 89.3%. The relative molecular weight of the enzymatic hydrolysates less than 2 000 Da was concentrated by HPLC analysis. 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH·) scavenging rate·OH scavenging rate and reducing power of the enzymatic hydrolysates were determined to assess their antioxidant activity in vitro. The results showed that the enzymatic hydrolysates had strong antioxidant activity. This study provided techinique support for the utilization of the lepidotrigla kishinouyi.